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Silver ring

Posted: Tue Mar 20, 2007 6:57 am
by Olis
Hello! This is my first post here at the indigo forums. I've used indigo for a couple of weeks now and I must say that it is the best free renderer I've ever used. This is a ring which I modeled in blender. I rendered it for about 9 hours.
Image

Posted: Tue Mar 20, 2007 7:10 am
by Kram1032
looks good! Although, the absorbtion of the ruby isn't high enough, I guess...
A little overexposured, too...
Which version did you use, which app, which exporter and which materials? (Especially: is the silver a Ag.nk-Phong?)

I know, lots of questions :D

Looks quite promissing

Posted: Tue Mar 20, 2007 8:26 am
by Olis
The indigo version I used is 07test5. It is really bright, I know, the burn is set to 1 because i wanted the background to be white. You're right about the metal. I used Ag.nk which I thought looked very good. The exporter is Blendigo v0.7t5 beta 4. I really like its material editor. On the ruby, which has a specular material, I set the RGB gain to 3. With the gain set to 1 it was way too transparent and as you pointed out it may still be too transparent. Thanks for the reply.

Posted: Tue Mar 20, 2007 8:31 am
by eman7613
i think the ruby would look better as a yellow diamond, but thats just me ;p

Posted: Tue Mar 20, 2007 8:51 am
by manitwo
cool - but one thing is missing: dof-blur :D

Posted: Tue Mar 20, 2007 9:03 am
by Kram1032
IOR of Ruby ~=1.762-1.770 did you use that?
Birefra...something = -0.008

I had an idea for using this: blend two materials:
one with IOR 1.762, one with IOR 1.770, let the rest at the same values ;) try to use more absorbtion and make it a bit more pinkish (look at wikipedia ;)) I have to try my IOR-Idea :D

Posted: Tue Mar 20, 2007 9:04 am
by Olis
Yes, I've noticed that in indigo07t5 DOF doesn't seem to work. The camera is focused on the upper part of the ruby but the ring is still in focus too. In fact, everything I've rendered in 07t5 is missing the blur.

Posted: Tue Mar 20, 2007 9:07 am
by Kram1032
Ah, that's confusing every one!

DoF = less blur, so if there stands "higher F-stop-value means more DoF", you have to reduce F-Stop for Blur ;) I think, you could set it down to 1 and it wont be too strong, but just try yourself ;)

Posted: Tue Mar 20, 2007 10:25 am
by F.ip2
9 hours? Argh it is pretty noise for that model. I thought MTL will be faster.
Are you using a noise map as a fine bump map?

You modeled the prongs wrong.
You do not just bend them. You cut out a 45 degree shape.
and bend the top part inwards to fill the space.
This way you have an edge which follows the gem cut.
Depending on the cut you can also use a burr to drill away the silver.

You also try to round the ends of the prongs as much as possible,
less friction. For that I use a special burnish tool. It is a concave shape.

Try to include a better change in the volume of the ring band.

Just a fine detail but it adds realism.


Also think about composition. I like cropping but the background is byfar to white and burning. With some better backdrop including shadows and the mentioned DOF your rendering will look much more realistic.

Check out:
http://www2.indigorenderer.com/joomla/f ... .php?t=286

He has some good tips on how to setup lights and use it artistically.
Also include light reflectors and other elements. Those will be shown in the reflections.


if you look up some photography tutorials about jewelry shooting you will find a ton of information. everything there you can apply into rendering.


Claas

Posted: Tue Mar 20, 2007 10:28 am
by DaveC
For a nice blurred DoF effect, you need a very low f-stop. 1 or 2. And you need to check the scale of your object. If your ring is 2 meters in diameter in indigo, you might not get very much blurring. if your ring is only 3 centimeters and your camera is very close up, the effect should be much more pronounced.

Posted: Tue Mar 20, 2007 10:31 am
by Kram1032
I tried my idea, but as expected, indigo can't blnd transparent things, yet...
But I thought, it just means with alphmap, as it worked with my clorophyll test...
Which is SSS glossy transp...

Posted: Wed Mar 21, 2007 8:29 am
by Olis
I've done a lot of experimenting and this is how it looks so far. I've changed the shape of the ring slightly and I have made a new mount for the gemstone, which has got a new colour. The DOF still won't work. I have tried to set it to the highest number and the lowest number but the blur won't show up. Currently the f-stop is set to 1.
Image

Posted: Wed Mar 21, 2007 8:42 am
by Kram1032
NOW it gets strane...
f-stop 1 means very much blur...
Where is the focus?

Posted: Wed Mar 21, 2007 8:54 am
by Olis
The focus is on the stone.

Posted: Wed Mar 21, 2007 9:08 am
by manitwo
how big is your model?